I've watched companies burn through six figures building software they could have bought for $200 a month. I've also watched companies duct-tape together five SaaS tools when a simple custom solution would have saved them thousands of hours. The build vs. buy decision is one of the most consequential technology choices a business makes, and most companies get it wrong.

Over 20+ years of leading technology teams, from enterprise environments at Disney and Universal to scrappy startups, I've developed a framework for this decision. It's not complicated. But it forces you to think clearly about what actually matters before emotions and vendor demos start clouding your judgment.

Why This Decision Matters More Than You Think

Build vs. buy isn't just a technology question. It's a business strategy question. The wrong call can tie up your development team for months, drain your budget, create ongoing maintenance burdens, or lock you into a vendor that doesn't fit how you actually work.

I see this constantly with my Fractional CTO clients. A founder decides to build a custom CRM because Salesforce "doesn't do exactly what we need." Eight months later, they've spent $180,000 and the thing barely works. Or the reverse: a company paying $3,000 a month across seven different tools, fighting with integrations that break every other week, when a focused custom build would have cost $40,000 and solved the problem permanently.

The stakes go up every year. Software is more expensive to build, more expensive to maintain, and the off-the-shelf options are better than they've ever been. Getting this decision right is table stakes for running a technology-informed business.

The 4-Question Framework

When a client comes to me with a build vs. buy decision, I walk them through four questions. In order. Each one narrows the field.

Question 1: Is This a Core Differentiator?

This is the single most important question. Does this piece of software directly contribute to what makes your business different? Is it the thing your customers choose you for?

If you're a logistics company and your routing algorithm is what sets you apart, build it. That's your competitive advantage. But your HR system? Your accounting software? Your email marketing platform? Those are not differentiators. Buy them.

I worked with a healthcare technology company that was building their own appointment scheduling system from scratch. When I asked why, the answer was "we want it to work exactly the way we want." That's not a differentiator. That's a preference. Their actual differentiator was their patient matching algorithm. We killed the scheduling project, bought Calendly's API, and redirected the engineering team to the thing that actually mattered.

Rule of thumb: If your competitors could use the exact same tool and it wouldn't hurt your competitive position, buy it. Save your building energy for the things only you can build.

Question 2: Does an Off-the-Shelf Tool Do 80% of What You Need?

This is the 80% rule, and it saves companies from themselves. If an existing product handles 80% or more of your requirements, you should almost always buy it. That last 20% feels important in a requirements meeting. It rarely matters as much as you think.

Here's what I tell clients: write down every feature you need. Now circle the ones that are actually critical for day one. The list usually shrinks by half. Then go look at what's on the market. If something covers most of what you circled, buy it and adapt your process to fit the tool.

Yes, you read that right. Sometimes the smart move is changing your process to match the software, not the other way around. Especially when the software was designed by a team of 200 people who've been thinking about this problem for a decade.

Question 3: What's the Total Cost of Ownership?

This is where most build vs. buy analyses fall apart. People compare the subscription cost of a SaaS tool against the development cost of building it. That comparison is wildly incomplete.

When you build, you're also paying for:

• Ongoing maintenance and bug fixes (typically 15-20% of initial build cost per year)
• Infrastructure and hosting
• Security patches and compliance updates
• Feature requests from users who now expect improvements
• Documentation and onboarding for new team members
• The opportunity cost of your developers not working on something else

When you buy, you're also paying for:

• Annual price increases (budget for 10-15% per year)
• Integration costs to connect with your other systems
• Training and change management
• Potential data migration costs if you switch later
• Customization or workarounds for the features that don't fit

I always model both scenarios out to a 3-year horizon. The math often surprises people. A $50,000 custom build that costs $10,000 a year to maintain looks different when you compare it to a $500/month SaaS tool. Over three years: $80,000 vs. $18,000. And the SaaS tool gets better every month without you lifting a finger.

This kind of analysis is central to technology strategy work. It's not glamorous, but it prevents expensive mistakes.

Question 4: Do You Have the Team to Maintain It?

Building software is the easy part. Maintaining it is where companies get buried. I need you to really hear this: every piece of custom software you build becomes a permanent obligation.

Before you commit to building, ask yourself:

• Do you have developers on staff who will maintain this long-term?
• What happens when the person who built it leaves?
• Can you afford to keep up with security updates and infrastructure changes?
• Is your team excited about maintaining this, or will it become the thing nobody wants to touch?

I've inherited codebases at multiple companies where a critical internal tool was built by a contractor who's long gone, nobody understands how it works, and the whole thing is held together by hope. Don't be that company.

When to Build

After running through those four questions, the "build" answer usually falls into a few categories:

• Competitive advantage. The software IS the product, or it directly enables what makes you better than competitors.
• Truly unique workflows. Your process is genuinely different from industry standard, and forcing it into existing tools creates more problems than it solves.
• Data ownership and control. Regulatory requirements, security concerns, or business model needs that mean you can't have customer data sitting in a third-party system.
• Integration glue. Small, focused custom code that connects your existing systems in ways no off-the-shelf tool handles. This is the most common legitimate "build" scenario for small businesses.

If you do decide to build, keep scope tight. Start with the minimum feature set that delivers value. Get it into real users' hands fast. Iterate from there. I work with clients on this through custom development projects, and the number one lesson is always the same: build less than you think you need.

When to Buy

Most of the time, for most businesses, the answer is buy. Here's when it's clearly the right call:

• Commodity functionality. Email, project management, accounting, CRM, file storage. These are solved problems. Don't re-solve them.
• Speed to market matters. If you need something working in weeks, not months, buy it. You can always replace it later.
• Limited technical team. If you don't have developers on staff, building creates a dependency on contractors that's expensive and risky.
• The market leader is really good. Sometimes the existing tool is just better than anything you'd build. That's fine. Use it.

The Middle Ground: Buy Then Customize

There's a third option that I recommend more often than pure build or pure buy: start with an off-the-shelf tool and customize it.

Most modern SaaS platforms have APIs, webhook support, and some level of configuration. You can often get 90-95% of what you need by combining a bought tool with light custom work on top. A custom integration here, an automated workflow there, a small internal tool that fills the gaps.

This approach gives you the best of both worlds. You get the reliability, ongoing development, and support of a mature product. And you get the specific functionality your business needs through targeted customization.

One example: I helped a property management company that was drowning in tenant communication. Instead of building a custom portal from scratch, we bought a standard property management platform and built a custom notification layer on top of it using their API. Total custom development cost was about $12,000. Building the whole thing would have been north of $150,000.

Common Mistakes I See Repeatedly

Over-building

The most expensive mistake. A company decides to build something, and scope creep turns a focused tool into a sprawling platform nobody asked for. The antidote is brutal prioritization. What is the one thing this needs to do well on day one? Build that. Nothing else.

Under-researching

I regularly talk to founders who say "there's nothing out there that does what we need" and then I find three tools that do exactly what they need within 20 minutes of searching. Before you build anything, spend real time evaluating what exists. Sign up for free trials. Talk to sales teams. Read reviews from companies similar to yours. This research is part of the job.

Ignoring Maintenance Costs

Building software has a sticker price. Maintaining it has a subscription price that never ends. Every line of custom code is a future liability. Dependencies get outdated. Frameworks release breaking changes. Security vulnerabilities pop up. If your total cost model doesn't include ongoing maintenance, your model is wrong.

Building for Edge Cases

"But what about the 3% of cases where we need feature X?" If you're building for the 3%, you're probably making the wrong decision. Handle the edge cases manually. Build for the 97%.

Vendor Lock-in Fear

Some teams avoid buying because they're afraid of getting locked into a vendor. This is a real concern, but it's often overblown. Most modern tools make data export straightforward. And the cost of avoiding vendor lock-in by building everything yourself is almost always higher than the cost of switching vendors later if you need to.

Putting the Framework Into Practice

Next time you're facing a build vs. buy decision, run through the four questions. Write your answers down. Show them to someone who will be honest with you. The framework won't make the decision for you, but it will make sure you're asking the right questions before you commit time and money.

And if you're not sure? Default to buy. You can always build later when you have more information about what you actually need. You can't un-build something you've already spent six months on.

The bottom line: Build what makes you different. Buy everything else. And when in doubt, start with a bought solution and customize it. Your future self will thank you.

Need Help With a Build vs. Buy Decision?

This is one of the most common things I work through with clients. If you're staring at a technology decision and want a second opinion from someone who's made this call hundreds of times, let's talk. I'll give you an honest assessment, even if the answer is "just use the free tier of that SaaS tool and move on."